Microwave & infrared (Edexcel GCSE Physics): Flashcards
📚Flashcards
Practise the cards
15 cards from this deck
ShowHide
Practise the cards
15 cards from this deck
Why are microwaves used in satellite communication
Why are microwaves used in satellite communication
Can pass through Earth's atmosphere
Why do communication microwaves differ from oven microwaves
Why do communication microwaves differ from oven microwaves
Must travel long distances without being absorbed
What molecules do microwaves heat in food
What molecules do microwaves heat in food
Water molecules
How far do microwaves penetrate into food
How far do microwaves penetrate into food
A few centimetres
How do microwave ovens cook food from inside
How do microwave ovens cook food from inside
Water molecules transfer heat to rest of food
What type of objects emit infrared radiation
What type of objects emit infrared radiation
All hot objects
Effect of temperature on IR emission
Effect of temperature on IR emission
Hotter objects give off more IR radiation
How do police use thermal imaging
How do police use thermal imaging
Detect suspects in the dark
How do security systems use infrared
How do security systems use infrared
Detect motion/heat to trigger alarms or lights
How do toasters cook food
How do toasters cook food
Use IR to heat food when absorbed
What does electric heater wire emit
What does electric heater wire emit
Infrared radiation and visible light
Distance range for IR communication
Distance range for IR communication
Short distances only
IR receiver position requirement
IR receiver position requirement
Must be in line of sight of emitter
What are optical fibres made of
What are optical fibres made of
Thin strands of glass or plastic
How does data travel through optical fibres
How does data travel through optical fibres
Total internal reflection